The present invention relates to a method and a system for connecting subscribers of a telecommunication network in a switching center that includes an input for receiving signaled data, a means for forming and processing connection-related data from the data received at the input side, and a means for signaling the processed data at the output thereof.
Due to the modernization of telecommunication networks, new signaling methods (analog, digital, ISDN) and the addition of available services in a switching center result in more expensive connection control. Where earlier a simple switching through of subscriber A to subscriber B on the basis of the selected call number was sufficient, now more and more information has to be taken into account when a call is switched through; e.g., the category of the call (telephone, fax, modem), the desired network operator, bearer capabilities (quality and data rate of the operator), category of the subscriber, etc. In the course of connection control, it is now necessary with increasing frequency to evaluate the data received at the outset, according to particular criteria, and to modify it if warranted.
In known apparatuses, the sequence program of the connection control must be modified correspondingly in order to enable the use of new services or information; i.e., the logic for evaluation and modification of connection-related data must be fundamentally reprogrammed. However, this is connected with a considerable expense that results in high costs for the network operator. In addition, errors can occur during reprogramming of the connection control which can lead to lasting problems.
From EP-0 540 256 A2, an arrangement is known for call handling in a switching means, in particular for the maximally flexible management of numbering plans of different communication networks. An adaptation of an existing switching means, given modifications or expansions of the numbering plan originally supported by it, is avoided by grammatically analyzing the numbers of the communication network according to the numbering plan, in the manner of a language in the mathematical/information-technological sense. Data structures independent of the numbering plan are thereby used for the determination of the call-related numerals and services. Thus, symbol strings are received whose contents are determined by the application of syntax and grammar according to the stored data structures, and a handling of the call is defined independent of the respective numbering plan. The dependencies of the switching means on the supported numbering plan are specified solely by the content of the data structures, so that for modifications or expansions of the already-existing numbering plan only corresponding adaptations of the definitions in the data structures are to be carried out. In this way, it is possible for the switching means to be able to implement any numbering plan by means of the arrangement for call handling.
From EP-0 557 645 A2, a method is known for the external calling of performance features of a switching means that includes an internal numbering plan in a communication network with an associated network numbering plan. A call processing means of the switching means thereby uses stored information such as syntax and grammar of the respective numbering plans. The switching means receives a call-related symbol sequence and interprets it as an equivalent access code of a performance feature, and subsequently calls it.
From the article xe2x80x9cSchema translation into a unified model for service operation,xe2x80x9d a model is known for service handling in which a mutual communication of processing systems becomes possible by translation of the respective individual local schema into a unified schema. From the article xe2x80x9cMapping strategies for a relational view of the No. 1A ESS translations data base,xe2x80x9d a method is known for the imaging, for modeling purposes, of a complex database for the example of a switching means. This database is constructed in structured form for a maximally effective call handling and storing of the data. The model creates an indirect interface to the database in order to apply a preceding or subsequent strategy for the management of the database accesses.
From U.S. Pat. No. 5,416,835, a method is known for the automatic identification of the type of signaling used on the basis of a call for the setup of a connection to a central switching means. Detectors for determining whether a two-tone multifrequent signaling is present are thereby arranged in the vicinity of the switching means. From U.S. Pat. No. 4,914,690 a universal interface is known between a private branch exchange and a central switching means, which enables support even of telephone installations that are not compatible with the private branch exchange, by means of standardized conversion.
It is therefore an object of the present invention to create a method and a system for processing connection-related data that is as independent as possible of the individual signaling methods and that can be adapted easily and economically.
This object is inventively solved in a method and system wherein, by means of a predetermined allocation with the aid of a predetermined parameter list, the connection-related data is converted into neutral parameters independent of the original format of the data. These parameters are then processed in their neutral format by the switching center. Thereafter, the data to be signaled at the output side is formed from the neutral parameters by means of the predetermined allocation, with the aid of the parameter list, by means of back-conversion.
According to the present invention, a system for the solution of the above-stated object includes a means for converting connection-related data into neutral parameters with the aid of a predetermined parameter list, a means for processing these neutral parameters independent of the original format of the connection-related data, and a means for conversion of the processed neutral parameters back into connection-related data with the aid of the parameter list; these back converted data being sent at the output of the switching center for connection controlling. For the processing of the neutral parameters, a data revaluing unit and a data modification unit are provided wherein the data revaluing unit is set up so as to evaluate the data received at the input side after conversion into neutral parameters, and the data modification unit is set up to modify the neutral parameters which are either dependent on the result of the evaluation by the data revaluing unit or dependent on the result of the allocation by the conversion means, or dependent on output-side control parameters. By means of this xe2x80x9cneutralizationxe2x80x9d of the connection-related data independent of the signaling method or, respectively, of the format and definition of this data, the evaluation and modification of the data can be executed in uniform fashion for all signaling methods and data formats.
Given the addition of new signaling methods or new services, it is often sufficient to add particular entries to the parameter list in order to ensure orderly allocation of newly incoming connection-related data into neutral parameters, wherein the evaluation thereof and back-conversion thereof is into format-dependent data. The sequence program of the data evaluation and modification accordingly remains unmodified so that in such cases the expense for adapting a switching center can be lowered considerably.
In a preferred embodiment of the inventive method, it is provided that each neutral parameter is formed dependent on the signaling method used, such as TUP, ISUP, MFC-R2, whereby a corresponding parameter set is defined in the parameter list for each allowed signaling method. In addition, in this embodiment it is useful to define for each parameter of the parameter list a particular data format and a particular value range.
Given the use of a digital transmission protocol for central signaling channels (CCS=Common Channel Signaling), such as ISUP, TUP, GSM, the connection-related data is that which is defined in the various signaling methods as messages serving for the connection setup (mandatory and optional messages) or, respectively, message contents; e.g., the entries of the initial address message (IAM) or, sequential address message (SAM) of an ISUP transmission protocol. Each message or, respectively, each individual message part, e.g., each entry of the ISUP message (IAM, SAM), is converted with the aid of the parameter list into a respective modification unit. After an evaluation by the data revaluing unit, the neutral parameters of the connection-related data can be modified dependent on this evaluation by means of a data modification unit. Alternatively, the neutral parameters of the connection-related data can be modified by a data modification unit already before their processing by the data revaluing unit, dependent on the result of the data allocation. It is likewise possible to subsequently modify the neutral parameters dependent on output-side control conditions. By this means, a maximally flexible evaluation or, respectively, modification of the data in their neutral format is possible.